頻率帶寬度 的英文怎麼說
中文拼音 [bīnlǜdàikuāndù]
頻率帶寬度
英文
bandwidth-
Based on the real situation of submarine and antisubmarine warfare ( asw ), according to the classical design theory of transducer or transducer array, a sonar will be researched and made, which has the feature of more wider bandwidth, more lower operating frequency, more lager radiation acoustic power, more farther operating distance, more higher researching efficiency and more higher directive accuracy
本文根據現代潛戰和反潛戰( asw )的實際情況,按照經典的換能器和基陣的設計理論,研製聲吶,旨在擴展其頻帶寬度、降低其工作頻率、增大其發射功率、擴大其作用距離以及提高其搜索效率和定向準確度。The factors limiting the frequency band of the wide - band amplifier are introduced. through analyzing the effects of the intrinsic parameters and parasitical on the frequency characteristics, a method of improving fr of mosfet by using short channel device and making mosfet work at the saturation region through raising vgs is put forward ; the effects of different kinds of circuit configurations on the frequency characteristics and the junction voltage on the voltage pattern circuit, current pattern circuit and frequency characteristics are analyzed. according to the linear theory of transconductance which is applied in the bit circuit, the current pattern amplifier circuit, current transfer circuit and output circuit which consist of mosfet and the wide - band amplifier composed of them are put forward
介紹了限制寬帶放大器頻帶寬度的因素,通過分析mosfet的本徵參數、寄生參數對頻率特性的影響,提出了採用短溝器件、使mosfet工作在飽和區、抬高柵源電壓等提高mosfet特徵頻率的方法;分析了不同電路組態對放大器頻率特性的影響、節點電壓對電壓模電路、電流模電路頻率特性的不同影響,根據應用於雙極晶體管電路的跨導線性原理,提出了採用mosfet構成的電流模放大電路、電流傳輸電路、輸出電路以及由它們所組成的寬帶放大器,獲得了良好的頻率響應。We use the term bandwidth to represent such a frequency range.
我們用頻帶寬度這個詞來代表這樣的頻率范圍。By making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution 、 high frequency accuracy 、 very fast frequency hoping with it, the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step. while the electronically tuned filter abates the image interference and notably improves the selectivity. the theorem of frequency synthesizer and center - frequency - fixed filter is simply but adequately introduced first in this paper
課題中所採用的pll或dds pll鎖相頻率合成方法充分發揮鎖相環良好的窄帶跟蹤濾波特性,並結合dds的高頻率解析度、高頻率精確度和高速頻率捷變等優點,分別實現了系統所要求的高質量寬帶本振源和小步長頻率捷變;採用電調諧選頻技術,則大大改善了接收機的選擇性和抗干擾能力。In this system two oscillator are used for mixing. pll for high local oscillator and dds + pll for low local oscillator. by making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution, high frequency accuracy, very fast frequency hoping with it, the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step
系統採用兩次混頻,其中高本振的設計採用pll鎖相環頻率合成來實現,充分發揮了鎖相環頻率合成器的優良特性,實現了系統所要求的高質量寬頻帶本振源;低本振採用pll + dds頻率合成來實現,結合pll優良的鎖相特性與dds的高頻率解析度、高頻率精確度等優點,實現了頻率的小步進高精度合成。Featured by wide band gap, high breakage electric field, high electron mobility, low dielectric constant, strong irradiation proof and excellent chemical stability, silicon carbide ( sic ), viewed as one of the most promising wide band gap semiconductors, is widely utilized in optoelectronic devices, high frequency and large power, high temperature electronic devices
被譽為最有潛力的寬禁帶半導體材料一sic ,因其具有禁帶寬度大、擊穿電場高、熱導率大、電子飽和漂移速度高、介電常數小、抗輻射能力強、良好的化學穩定性等優異的特性,被廣泛地應用於光電器件、高頻大功率、高溫電子器件。Method for measuring effective output power bandwidth for institutional audio - visual equipment used primarily for speech
用於演講的教學視聽設備的有效輸出功率頻帶寬度的測量方法Based on the dds technology, the waveform generator first stored data in high speed ram, then used dac to synthesize waveform by the data. many waveforms could then be generated easily. besides, the wave generator could get high performance on frequence resolution and stability, phase continuum, relative bandwidth etc. the dds technology was widely used in frequence synthesis field
基於dds技術的波形發生器以高速存儲器作為波形數據查找表、通過高速d / a轉換器對存儲器的波形進行合成,可以靈活產生多種波形,同時具有頻率解析度高、頻率穩定性好、頻率轉換快、相位連續性好以及相對帶寬較寬等特點。Verification regulation of wide band frequency stability measurement set in time domain
寬頻帶頻率穩定度時域測量裝置檢定規程It has wide frequency width and high frequency relution. the maximum output frequency can get to 80m and the highest frequency relution can get to 1 u hz, the waveform memory is 64k. it has the important reference value for three classical structures - pc bus card, stand alone, vxi module
該任意波形發生器不僅能產生正弦波,方波,三角波等常用的標準信號,還可根據用戶的需要生成任意波形,具有寬頻帶,高的頻率解析度等特點,其波形最高輸出頻率可達80m ,頻率解析度可達1 hz ,波形最大存儲深度為64k ,對于目前三種典型的任意波形發生器的結構? pc總線插卡式,獨立儀器, vxi模塊都有重要的參考價值。The spot responder system which is the necessary part of ctcs is analyzed in the dissertation and three key technologies of the channel in the responder system are researched. firstly, a new kind of rectangular plate magnetic inductive loop antenna is designed to transmit the power frequency. researching the near field inter - inductive characters, the relationship among the inductive efficiency, the perimeter and the conductor width of the antenna is found out
本文在對ctcs中的點式應答器系統原理及組成進行分析和消化的基礎上,對系統中通道的幾個關鍵技術進行了詳盡的研究,主要分為三個方面: 1 ,提出並研製了新型的片式環形磁感應天線,並對傳輸能量載波的天線的近場互感特性進行了分析,得到互感效率隨天線的周長大小以及導帶寬度的變化規律,並通過計算機模擬和試驗對天線的近場波瓣圖進行了研究;通過分析寬帶匹配技術中的實頻法理論,設計了信號載波天線的寬帶匹配網路。Two cold - test parameters determine the working voltage, frequency band, efficiency and gain of twt. they are dispersion and interaction impedance of the slow - wave structures ( sws ) in twt, which are very important targets for twt
行波管慢波結構的色散和耦合阻抗是行波管設計中兩個非常重要的冷參量,它們決定了整支管子的工作電壓、頻帶寬度、工作效率和增益。The controlled object hyvp ( hydraulic pressure vibration platform ) has the property of big loading pressure and rating power, so it need considerable transmitted and control power, it also has the property of high - level math model, and narrow frequency width in closed - loop, and bad stability. this thesis is based on the hpvs in the “ tiema project ”
被控對象(液壓振動臺)具有負載壓力和額定功率相當大的特點,因此要求傳輸和控制的功率要相當可觀;而且它還具有數學模型階數高、閉環頻帶寬度窄、穩定性差等特點。Thirdly, a modified extended chirp scaling ( ecs ) algorithm is presented, which solves the problem of producding fine focused images in the class of chirp scaling ( cs ) algorithm. lt can be used for uwb - sar imaging effectively. the phas e error produced by cs operation are analyzed. a windowed process in two dimension frequency domain before cs operation are proposed. it can improve the quality of image and widen the effectively swath and increase the peak to sidelobe ratio ( pslr )
然後針對chirpscaling ( cs )類演算法不能對參考點精確聚焦的問題,提出了一種改進的擴展cs ( ecs )演算法,實現了對uwb - sar的高效成像;分析了cs操作產生的相位誤差,提出在cs操作之前在二維頻率域對信號加窗,除有效提高信號的峰值旁瓣比( pslr )外,還可以提高圖像質量,增加有效測繪帶寬度。Specialties : the range of center frequency it can achieve is bigger than one - piece filter ; at the time it has the features of wide pass - band, low insertion loss and high restraint outside the band
特點:可實現的中心頻率范圍較單片濾波器寬,通帶寬度范圍大,插入損耗小,帶外抑制高。At last we introduce the realization of all the parts, the problem in the circuit design and the measured data. the results show that the designed system has met the requirement. in this dissertation, direct digital synthesis technology has been used in the phase - locked frequency synthesizer, which can make full use of the characteristics of direct digital synthesis technology such as flexible output wave shape and continuous
本課題將直接數字式合成技術用於鎖相頻率合成器中,該方法將直接數字合成的特點,如輸出波形靈活且相位連續、頻率穩定度高、輸出頻率解析度高、頻率轉換速度快、輸出相位噪聲低、集成度高、功耗低、體積小等與鎖相環路的頻帶寬、工作頻率高、頻譜質量好等優點有機的結合起來,從而在寬帶的條件下實現了比較好的雜散性能和相噪。A chirp - z transform ( czt ) algorithm on the which is similar to range - doppler algorithm is studied, and the effective swath width is analyzed. secondly, a modified block czt algorithm is presented, which improvs the computational efficiency of the high - resolution sar imaging with wide swath
其次研究了一種與距離-多普勒演算法類似的線性調頻z變換( czt )演算法,分析了有效測繪帶寬度的問題;提出了一種改進的分塊處理czt演算法,提高了對大場景高解析度sar成像處理的計算效率。Due to its intrinsic merits, such as wide band gap, high electron saturated drift velocity, high melting point, good coefficient of thermal conductivity, anti - radiation and good chemical stability, gallium nitride as a direct band gap semiconductor has become the promising material for the application of short - wave light - emitting devices and high temperature, high frequency and high power electronic devices
Gan是直接帶隙半導體材料,以其禁帶寬度大、電子飽和漂移速度大、熔點高、熱導率高、抗輻射能力強和化學穩定性好等優點成為製造短波長光發射器件及高溫、高頻、大功率電子器件的理想材料。The low frequencies in mra are in good resolution, but the high ones are not. however, the wavelet packet can overcome the shortcomes in high frequencies and it can make the width of each frequency - band same. however, the calculations are large as the decomposed layer is much high
多分辨分析mra的低頻解析度較好,但其在高頻部分卻不太理想,而用小波包可以克服mra在高頻部分的缺陷,並且可以做到每個子頻率帶寬都相同。The modulating signal is generated in the way of direct digital synthesizer technology. the signal has many characteristics such as ultra wide frequency bandwidth, ultra high frequency resolution and ultra good phasic continuity, etc. thus it can be achieved the high frequency and amplitude stability of the modulating signal
本文採用了數字頻率合成技術( dds )來產生調制信號,它具有超寬的頻率帶寬、超高的頻率解析度和相位連續性等特點,可以實現聲光調制信號的頻率和振幅的高穩定性。分享友人